Cardiovascular disease (CVD) and stroke are two of the leading causes of morbidity and mortality among adults in North America and are strongly determined by levels of common CVD risk factors including hypertension, diabetes, obesity, cigarette smoking, and dyslipidemia. Specific extracellular RNAs regulate key processes central to the pathogenesis of CVD and several small human studies have associated extracellular RNAs with specific forms of CVD. We postulate that the expression of plasma RNAs change over time and is influenced by the duration and intensity of exposure to CVD risk factors, relates to subclinical atherosclerosis phenotypes, and will therefore be useful predictors of incident CVD events. We intend to further explore and validate the diagnostic and prognostic utility of extracellular RNAs associated with CVD and preclinical CVD phenotypes in our community-based cohort study in a hospitalized sample with acute coronary syndromes. To accomplish these aims, in the U2 phase of our study we will use an optimized non-commercial isolation method for high-yield plasma RNA extraction as well as high-throughput sequencing to identify known and as-yet undiscovered extracellular circulating RNAs, thereby developing a broad panel of plasma-derived extracellular RNA biomarkers (including miRNA, piRNA, noncoding RNAs) to screen 2914 participants in the Framingham Heart Study (FHS) Study (Offspring Exam 8). In the U3 phase of the application, we will further evaluate changes in circulating RNAs over time and in relation to incident CVD and disease progression, by screening the same individuals 5 years later (Offspring Exam 9). We will then examine associations between extracellular RNAs and CVD-related prognosis in ~400 participants of TRACE-CORE (Transitions and Research in Acute Coronary Events - Center for Outcomes Research and Education). We will perform exploratory analyses to determine if these methods can be extended to non-CVD populations. Last, we will partner with industry leaders to develop a quick and effective point-of-care test for extracellular RNA profiles associated with disease.